Hello.
Unfortunately, in the free version of Booking Calendar is not possible to use the separately the calendar and booking form shortcodes, which have to work together.
You can configure the booking form as you are need at the any paid version of plugin at the Booking > Settings > Fields page.

P.S. In the free version, you can only try to insert the special text using the jQuery. You will be need to load this special JavaScript in some of your JS files and use the “insertAfter” or similar command. Please check here. But still we are recommend to use the paid version, where you can easily configure the booking form.